Rule : If a number is divisible by both 3 and 2, the number is also divisible
by 6. So, for a number to be divisible by 6,
(I) The number should end with an even digit or 0 and
(II) The sum of its digits should be divisible by 3.
For example :
(1) 63924 : The first condition is fulfilled as the last digit (4) is an even
number and also (6+3+9+2+4=)24 is divisible by 3; therefore,
the number is divisible by 6.
(2) 154 : The first condition is fulfilled but not the second, therefore, the
number is not divisible by 6.
(3) 261 : The first condition is not fulfilled, therefore, we don't need to
check for the 2nd condition.